Pelvis - Sexual Dimorphism

• Pelvis morphology is adapted to demands of bipedal locomotion & childbirth.
• Male & female pelves are not dichotomous during pre-pubertal development.
• During puberty, female pelvis transitions to wider, shallower morphology

– Accommodation of neonate during childbirth. Female pelvis is generally wider.

• Laterally flared ilia

– Shallow (superior-inferior)

• Wide (left-right)
• Wide, oval-shaped pelvic inlet
• Wide, curved pubic arch
• Wide, curved greater sciatic notch
• Anterior tilt

Male pelvis is generally narrower and more angular.

• Superiorly flared ilia

– Deep (superior-inferior)

• Narrow (left-right)
• Narrow, aka, "heart-shaped" pelvic inlet
• Narrow, angular pubic arch
• Narrow greater sciatic notch
• No anterior tilt (vertical)

Additional Images of the Pelvis Fischer, Barbara, and Philipp Mitteroecker. “Allometry and Sexual Dimorphism in the Human Pelvis.” The Anatomical Record 300, no. 4 (April 1, 2017): 698–705. https://doi.org/10.1002/ar.23549. ———. “Covariation between Human Pelvis Shape, Stature, and Head Size Alleviates the Obstetric Dilemma.” Proceedings of the National Academy of Sciences 112, no. 18 (May 5, 2015): 5655–60. https://doi.org/10.1073/pnas.1420325112. Huseynov, Alik, Christoph P. E. Zollikofer, Walter Coudyzer, Dominic Gascho, Christian Kellenberger, Ricarda Hinzpeter, and Marcia S. Ponce de León. “Developmental Evidence for Obstetric Adaptation of the Human Female Pelvis.” Proceedings of the National Academy of Sciences 113, no. 19 (May 10, 2016): 5227–32. https://doi.org/10.1073/pnas.1517085113. McKinley, Michael, and Valerie O’Loughlin. Human Anatomy. 3rd ed. New York, NY: McGraw-Hill, 2012. Image Credits: Gray241-Sexual Dimorphism (Two Forms). March 27, 2004. Photo. https://www.flickr.com/photos/teresa-stanton/2408968222/. ———. Gray242=Sexual Dimorphism (Two Forms). March 27, 2004. Photo. https://www.flickr.com/photos/teresa-stanton/2408968224/.